The Government's asset sales programme now seems to rely on a very ill-defined piece of string - the length of time it will take for the Maori Council's legal challenge to wend its way to a conclusion.

OPINION:
As far as Prime Minister John Key is concerned, the sales - starting with 49 per cent of Mighty River Power - are ''completely on track''.

The Government had always expected the legal challenge and was glad it happened sooner rather than later, he told the House yesterday.

As an expression of confidence it is no less than you would expect from the Government and, in particular, the current prime minister. The alternative: ''We have no idea when the case will be resolved and the asset sales programme is now on the never-never'' is inconceivable.

But it is worth remembering the Government was briefly confident its original timetable for the first float, starting about now, would not be affected before it was forced to postpone it until March-June 2013.

Nor is any official answer available.

Asked for an estimate of the time for litigation to make its way through the Appeal Court to the Supreme Court, Attorney-General Christopher Finlayson's office and the Justice Ministry effectively said ''no idea''. Mr Key has pointed to a recent British case that was fast-tracked through to the Law Lords in just a few weeks, although the Crown's lawyer, David Goddard QC, argued in court that the prospect of a judgment and appeals by March were getting ''tight''.

Labour's shadow attorney-general, Charles Chauvel, took a stab at mid-2013 if both higher courts agreed to ''expedition'', and convene full benches for the hearing.

According to one prestigious law firm, Mr Chauvel may be being generous. A realistic timetable, taking into account time to consider an appeal, prepare arguments and to deliberate, would be about this time next year.

The process will put the judiciary into its discomfort zone, where the Government's right to act might be frustrated by the courts' speed in processing legitimate legal questions.

But as High Court judge Ronald Young pointed out, in setting a November 26 date for the first substantive hearing, it would be ''fool's pace'' to go faster and risk compromising quality with haste.

A hearing in a month ''would be pretty speedy ... given the significance'' of the case, he said.

The short answer is that no-one knows when the Maori Council challenge will finally be resolved, or what further delays may ensue if it ultimately wins its argument about the asset sales compromising its rights under the Treaty.

There is also considerable uncertainty around the breadth of any ruling come November.

This week, Maori Council lawyer Felix Geiringer foreshadowed his argument that the Crown had made a material error of fact in asserting that in common law, no-one owns water.

For his part, Mr Goddard argued the Crown did not expect the High Court case would try to resolve all questions related to the ownership of water in New Zealand.

However it pans out, the legal challenge continues to cast a huge shadow of uncertainty over the rest of the Government's term.

As time passes, the sales get harder and harder and the economic climate here and overseas becomes more uncertain.

If Rio Tinto carries through on its threat to pull out of the Tiwai Pt smelter, the whole shape of the electricity market - and hence the value and returns on the Crown's energy assets - becomes more problematic.

Labour leader David Shearer was yesterday also pointing out the flagging market for state asset sales worldwide.

A mandate may be a mandate, but as the election gets closer, as the anti-asset sales referendum gets closer and if the Government's popularity erodes, Government MPs will become more risk-averse. A further delay past June next year will essentially leave the Government only two slots to effect sales; October 2013 and early 2014, assuming a sale through the election campaign of late 2014 can be ruled out.

That would leave the Government facing a sort of political double jeopardy, campaigning again in 2014 (from a much more exposed position) for three of the same partial sales it promised in 2011.

It is all a far cry from the way the Government, flushed with success, set out its asset sales programme after the 2011 election.